Trouble in the Silk Road empire led Ross Ulbricht to put a hit on a user:

On or about March 29, 2013, ROSS WILLIAM ULBRICHT, aka “Dread Pirate Roberts,” aka “DPR”, aka “Silk Road”, the defendant, in connection with operating the Silk Road website, solicited a Silk Road user to execute a murder-for-hire of another Silk Road user, who was threatening to release the identities of thousands of users of the site.
But he didn’t want to overpay for it:

On March 31, 2013 DPR responded: “Don’t want to be a pain here, but the price seems high. Not long ago, I had a clean hit done for $80k. Are the prices you quoted the best you can do? I would like this done asap as he is talking about releasing the info on Monday.” Through further messages exchanged on March 31, 2013, DPR and readandwhite agreed upon a price of 1,670 Bitcoints – approximately $150,000 – for the job.